Hand-screw.



Patented May 27, |902. C. H. LINDSTROM L. E. CHRISTIANSEN.

H A N D S C R EW.

(Application led Aug. 12, 1901;)

(No Model.)

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limiten Srnrns PATENT OFFICE.

CHARLES II. IJINDSTROM AND LOUIS E. CHRISTIANSEN, OF CHICAGO,

LLINOIS.

HAND-SCREW.

SPECIFICATION forming part of Letters Patent N o. 700,952, dated May 27, 1902.

Application tiled August 12, 1901. Serial No. 71,825. (No model.)

To @ZZ whom it may concern:

Be it known that we, CHARLES II. LIND- srRoM and Louis E. OHRISTIANSEN, citizens of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented new and useful Improvements in Hand-Screws,of which the following is a specification.

This invention relates to hand-screws such as are employed by cabinet-makers; and the object of the present invention is to provide a hand-screw with means whereby the mov-v able and fixed jaws may be quickly adjusted toward or away from each other to bring the same into the desired relation to the object to be clamped between the jaws, thus doing away with the slow and tedious process of manipulating the screws in order to effect the desired adjustment.

With the above general object in view the invention consists in the novel construction, combination, and arrangement of parts hereinafter fully described, illustrated, and claimed.

In the accompanying drawings, Figure lis a plan view of a hand-screw with theimprovements applied thereto. Fig. 2 is an edge View of the same. Fig. 3 is a longitudinal section through the movable jaw.

Similarnumerals ofreference designate corresponding parts in the several views.

Referring to the drawings, 1 designates the fixed jaw, and 2 the movable jaw, of a springclamp, while 3 designates the fulcrum-screw,

and d the clamping-screw, both of said screws' being provided with the usual operating-handles Each of the screws 3 and 4 has a swiveled engagement with the fixed jaw4 1, which is accomplished by inserting keys or pins C through transverse openings in the fixed jaw l, the said screws engaging annular grooves 7 formed in the keys or pins where they enter the xed jaw. This establishes a swiveled engagement between the screws 3 and 4: and the fixed jaw l.

The movable jaw 2 comprises twin sections 8, and said sections are provided in their meeting surfaces with threaded openings 9 for the reception of and engagement with the screws 3 and 4i. One of the sections S is provided in its outer surface with a recess 10, in

which is fitted a washer 1l. VSaid recess l0 is of sufficient depth to receive the crown 12 of a yoke or fork, which comprises parallel arms I3. The arms 13 pass through openings in the washer Il, while the crown or head l2 of the yoke lies entirely withinthe recess 10 and affords no projection beyond the outer surface of the movable jaw. The arms 13 also pass through a second washer 14, seated iiush in the recess in the opposite section 8 of the movable jaw, as clearly shown in Fig. 3, and the extremities of said arms are connected by means of a pin 15, which forms the fulcrum of a cam 16, which operates against the washer 14: and serves to force the sections of the movable jaw together. Said cam is provided with a dwell-surface 17, which is adapted to bear againstthe movable jaw when the cam is thrown to its limit in one direction, and the cam is further provided with a lever 18, by means of which it may be manipulated, the said lever being adapted to extend across the outer surface of the movable jaw, as shown in Fig. 2, when said cam is in its operative position.

In order to force the sections 8 apart and release the movable jaw from the screws 3 and 4 for the purpose of allowing the movable jaw to be quickly adjusted toward and away from the fixed jaw, spiral springs 19 are disposed around the arms 13 of the yoke or fork and arranged within a recess 20, formed in the meeting faces of the sections 8, as shown in Fig.` 3. The said springs 19 are arranged aboutmidway between the screws 3 and 4. In vorder to insure the movement apart of the projecting ends of the sections 8, said sections are provided with oppositely-located mortises 21 in their meeting faces and near their projecting ends, in which is placed a pin 22, which is surrounded by a supplemental coil-spring 23, said spring acting by its expansive properties to move the sections 8 apart when the clamping-pressure is relieved by releasing the cam 16. j

From the foregoing description it will be seen that by rocking the cam-lever 18 outward the pressure of `Ithe cam 16 is relieved and the springs 19 and 23 are allowed to expand and force apart the sections 8 of the movable jaw. This eifects a disengagement IOO between the movable jaw-sections and the fulcrum and clamping-screws and admits of the movable jaw being quickly adjusted in either direction along the screws. After the movable jaw has been adjusted into the de sired relation tolthe work the cam is operated to draw the movable jaw-sections together. The threaded engagement between the movable jaw and screws is thus reestablished and the operation of clamping the work may then be completed by a slight turning movement of either one of the screws.

As the yoke engages each `jaw at two points it prevents them from vmoving laterally in opposite directions and holds them in the same plane at all times. The advantages of i this construction are obvious, for should the Having thus described the invention, what is claimed, and desired to be secured by Letters Patent, is-

In a hand-screw, the combination with fulcrum and clamping screws; of a fixed jawv having a swiveled engagement with said screws, and a movable jaw having a threaded engagement with said screws, the movable jaw comprising sections adapted to be moved toward and away from each other and into and out of engagement with the screws, a U-shaped yoke slidably mounted in parallel apertures in the jaw-sections, the intermediate portion of the yoke lying in a recess in one of the sections, a cam fulcrumed between the ends of the arms of the yoke and adapted to force the sections together, expansive springs coiled around the arms of the yoke and acting in opposite directions on the movable jaW-sections, and an auxiliary eXpansive spring mounted between the projecting ends of the movable jaw.

In testimony whereof we afix our signa; tures in presence of two witnesses.

CHARLES I-I. LINDSTROM. LOUIS E. CHRISTIANSEN.

Witnesses: f

JOHN W. BOGREN, ANTONIO J. BRIGNADELLO. 

